I had this engine and heads rebuilt and I put it back in the truck and put the heads on,intake manifold ect. Got about 400 miles on it now and it still smokes (oil smell) alittle when I start it up then it clears up. What might be the cause?

 

Sounds like valve seals. Did they change them when they rebuilt the heads? When valve seals start to get worn the oil leaks past them into the combustion chamber when you leave it sit for awhile. If your using synthetic oil it will sometimes do this were as conventinal will not. Just a thought.

 

Yes I was told buy the builder all the seals were replaced new and the seals wouldn't cause this anyway. I'm starting to believe he is full of &^%$ I have wished a hundred times I'd just done it myself and ask you guys for advice as I needed it. This is a great forum and I have learned alot already. I am using 5w30 mobil 1 syn so off to get oil and change it. What would you recommend I use?

 

Im not saying that synthetic oil is your problem. Its just something that happens sometimes. I would change the oil over to conventional oil for what it cost and how easy it is to change just to see if it still smokes. Just buy a good quality conventional oil. Valvoline, Castrol, Pennzoil, any of them. Let us know how it goes.

 

Ok will do and I agree for the cost and easy to do it's worth a shot vs replacing the seals!

 

Smoke on start-up is a sign of bad valve guides and/or valve seals.